I admit it.  While I have been slowly gathering the items required to
finish up Alien Arena and release it, I have been finding other
busy-work to do instead, unable to quite bring myself to face the
daunting task yet.  But I hope you'll agree that this particular bit of
work was worth the effort.  Thanks to Joe Magiera for letting me use his
hardware to test out the ROMS, and for the screenshot.

Here's the zip file:

http://www.backglass.org/williams/blast30.zip

Here's the screenshot:

http://www.backglass.org/williams/blaster_screenshot.jpg

Here's the readme from the zip file:

         The mythical 30-wave version of Blaster!
         ----------------------------------------

When Blaster was first put out at a test location in late 1983,
it had 30 waves and allowed you to continue a game by spending
another credit.  By the time the game went into production in
early 1984, the program had been modified to have 20 waves, and
no buy-ins allowed.  Presumably this was done as a result of
more location play-testing, but I believe this original version
is the far superior game.  More enemies, more diabolical levels,
it has everything an RGVAC Blaster owner could want in the game!
(Though perhaps I can see how it would have been too much for
people paying for the learning curve a quarter or two at a time.)

Considerable archaeological effort was expended to resurrect
this long-lost version of a rare but enjoyable video game from
the classic era.  Bowing down before the genius of Vid Kidz, I
now present the ultimate Blaster modification:

Only 8 of the 17 main game ROMs need to be changed.  The ROM
number of the file suffix matches the ROM number on the label
of the chip to be swapped out.  You will need three 27128s,
three 2764s, and two 2732s.  (Don't yell at me, I didn't design
this whacky setup -  I'm just providing ROM data!)

                 BLASTER.3  - 27128
                 BLASTER.4  - 27128
                 BLASTER.7  - 27128
                 BLASTER.11 - 2764
                 BLASTER.12 - 2764
                 BLASTER.13 - 2764
                 BLASTER.16 - 2732
                 BLASTER.17 - 2732

Program them, label them, swap them out for the originals, and
prepare to be amazed!

HUGELY IMPORTANT NOTE:  After upgrading and before turning your
game on, pull the batteries and wait a minute.  Then replace the
batteries and with the coin door *open*, turn the game on.  It
will complain of adjustment failure and tell you it has reset
everything.  Now with the coin door still open, turn the game
off and on again, and you should be all set.  Do *not* advance-
switch your way out of the failure message, you must power cycle.
Apparently the CMOS RAM layout is similar enough between the two
versions that when going back to this previous version it gets a
little confused unless you reset the memory completely like this.
If you don't do this step, the game will seem to work but things
will be off here and there in weird ways.

Enjoy!